Folded quarter-wave patch antenna

Abstract

A folded quarter-wave patch antenna which includes a conductor plate having first and second arms spaced apart. A ground plane is separated from the conductor plate by a dielectric substrate and is approximately parallel to the conductor plate. The ground plane is electrically connected to the first arm at one end. A signal unit is electrically coupled to the first arm. The signal unit transmits and/or receives signals having a selected frequency band. The folded quarter-wave patch antenna can also act as a dual frequency band antenna. In dual frequency band operation, the signal unit provides the antenna with a first signal of a first frequency band and a second signal of a second frequency band.

What I claim as my invention is: 
     
       1. A folded quarter-wave patch antenna, comprising: a folded conductor plate formed from a single conductor and having a first end and a second end, said conductor plate forming first and second arms in parallel with each other,   wherein a signal unit is coupled to said first arm, said signal unit feeding said antenna a first signal of a first frequency band such that said first signal creates surface current on said conductor plate, said surface current being substantially greater in magnitude in said first arm then in said second arm; and   a ground plane separated from said conductor plate by a dielectric substrate, said ground plane electrically connected to said conductor plate first end, said conductor plate second end electrically isolated from said ground plane.   
     
     
       2. The folded quarter-wave patch antenna according to claim 1, wherein said ground plane is substantially parallel to said conductor plate. 
     
     
       3. The folded quarter-wave patch antenna according to claim 1, wherein said ground plane is electrically connected to said first arm at one end. 
     
     
       4. The folded quarter-wave patch antenna according to claim 1, wherein the length of said conductor plate is approximately λ/4, said λ being a wavelength of said first signal. 
     
     
       5. The folded quarter-wave patch antenna according to claim 1 wherein the length of said first arm is approximately λ/8. 
     
     
       6. The folded quarter-wave patch antenna according to claim 1 wherein the length of said second arm is approximately λ/8. 
     
     
       7. The folded quarter-wave patch antenna according to claim 1, further comprising a signal unit coupled to said first arm, said signal unit feeding said antenna a first signal of a first frequency band, said signal unit feeding said antenna a second signal of a second frequency band. 
     
     
       8. The folded quarter-wave patch antenna according to claim 1, wherein said first arm resonates at said first frequency band, and said second arm resonates at said second frequency band, wherein said folded patch antenna acts as a dual frequency band antenna.